Lifting-jack.



E. M. ROBINSON.

LIF'I'ING JACK.

APPLIGATION FILED H1B. as, 1901.

No nomi..

5 SHEETS-SHEET 1.

wlllllllilli'' No. 739,619. V PATENTBD SEPT. z2, 1903-. E. M. RoBINs'oN mmm JAGK. APPLIGATIQN FILED FEB. 25, 1901. I E0 MODEL. 5 SHEETS-SHEET 2.

PATBNTBD s511122, 190s.

Y E. M. ROBINSUN.

LIFTING J-AGK.l PPLIGATmN FILED FEB. 25, 1901.

s sums-snuff 4.

H0 MODEL.V

N0. 739.619. y PATENTED sEPT.`22, 1903'. E. M. ROBINSON. LIFTING JAGK.

APELIUATION FILED FEB. 25,1901.

5 SHEETS-SHEET 5.

N0 MODEL.

vZ5 fw Y UNITED STATES l recent-.ea september 22, 190e.

PATENT OFFICE."

LllTlNG-JAGK.

SPECIFICATION forming-part of Letters Patent No. 739,619, dated September 22, 1903.

Application filed February 25, 1901. Serial No. 48,798. (No model.)

To aZZ whom it may concern:

Beit known that I, EUGENE M. ROBINSON,

a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Lifting-Jacks, of which the following is a specification, reference being had to the accompanying drawings, in which simil ariigures indicate the same parts throughout the several views.

My invention relates to a lifting-j ack, and particularly to one adapted to lower the load.

The object of my invention is to provide'a jack suitable for use around a railroad in lifting and lowering track, cars, engines, and other heavy objects, which will be of economical construction and efficient in operation and which will securely hold the load in any desired position.

My invention is a distinct improvement upon the jack shown, described, and claimed in my Patent No. 555,265,issued February 25, 1896, in that the load can be pumped down as well as up and in features which enable the load to be lifted more efficiently.

It also consists in the details of construction hereinafter more fully described and claimed. In the drawings, Figure 1 is a side view of my improved lifting-jack, showing the position of the pawls whenthe lifting-lever is in the highest position and Fig. 2 the same view in section when the lever is near the bottom of its stroke. Fig. 3 is a sectional view 'of the jack when the lever is at the lower end of Vits stroke and the pawls are entirely disengaged from the lifting-bar, so that the jack can vbe removed from under the load. Fig. eis'a side sectional view of my down-pump jack with the lifting-lever in its highest position. Fig, 5 shows the same jack when the lever has been lowered a little, so that the lower pawl has been fully tripped. Fig. 6 shows it when the lever is near the bottom of its stroke, the lower pawl being in engagement and the upper pawl just ready to trip, the dotted lines showing the upper pawl tripped. Figs. 7, 8, 9, and 10 are detail sectional views on the corresponding lines of Fig. 4.

Rising from the base is the upright standard 1.6,preferably of cast-iron,having attached thereto the handles 17, so that it can be conveniently carried about. Slidably mounted in this standard 16 is the notched lifting-bar 18, provided at its top with a head 19, adapted to bear against'a high load, and at its bottom with a foot 20, adapted to fit under a railroadrail or other object near the ground.

` Pivoted to the standard 16 at 21 are two links 22. The upper end of each link is pivotally connected at to one fork 24 of the lifting-lever socket 25, in which a pole of any desired length is inserted. The forks 24 of the lifting-lever socket embrace the standard 16, as shown, and have the pawl 2G, pivotally connected to them by means of the bolt 27. This paw] has teeth, as shown, adapted to engage those on the lifting-bar, and also has integral with it the sleeve 2S, inclosing the lifting-bar, so as to avoid a diagonal thrust on the lifting-pawl, which would cause friction. This sleeve 28 also serves the purpose when the pawl is in certain positions of locking the pawl to the lifting-bar. The upper' inner side of the sleeve is cut away in the line 29, so that the pawl and sleeve may be tilted upward to release the pawl from the teeth of the lifting-bar. On'each side of the sleeve 28 is a tooth or prong 30. These teeth are about in the middle of the sides, as shown, and the sides of the sleeve are out away from these teeth 30 in the slantin g lines 31 and 32, so that the sides of the sleeve will not interfere with the action of thefti-eth 30 on the upper pawl, to be hereinafter described. While in the preferred form of construction I pivot the pawl 2.6 to fork 24, many other forms of construction Vmay be used-as, for instance, those shown in 'my Patent No. 555,265, above referred to. Pivoted to the standard 16 by means of the bolt 33 is the upper pawl 34. This pawl also has integral with it a sleeve 35, surrounding the liftingbar 1S- On the lower edges of this sleeve are prongs or teeth 36. The metal of the sides of the sleeve is cut away, as shown, and the teeth are so located that when the liftinglever is dropped to its lowest position the teeth on this sleeve will clear those on the lower pawl, as shown in 2, and when the lower pawl is tilted up by hand and thrown out of engagement with the lifting-bar the teeth on the two sleeves will hook together, as shown in Fig. 3. This arrangement of IOO these teeth is important in that it gives me a lift of an extra tooth per stroke over what was possible with the construction shown in my former patent, above referred to. v

On the back of the lifting bar 18 are notches or teeth 37, in which b oth of the pawls above referred to iit. Vhen the jack is used as a lifting-jack, the only necessary parts are those heretofore described, and when the outer end of the lifting-lever is depressed the power-pawl, and with it the lifting-bar, is elevated. The upper pawl of course clicks idly past each notch of the lifting-bar as it goes up and teeth 30 clear teeth 36. Vhen the lifting-lever is raised, the upper pawl holds the bar in position, while the lower pawl clicks down the teeth of the bar. Vhen it is desired to lower the lifting# bar, the lower pawl is tilted by hand and elevated until the hooks 'or teeth 30 engage teeth 36. Then a slight downward motion of the lifting-lever throws the upper pawl out, as shown in Fig. 3, and the lifting-bar drops of its own weight.

In order to give my jack the ability to pump the load downward as well as upward, I slidably mount in the back of the standard 16 a plate orbar 4l, which has a spring-catch 42, adapted to hold this baror plate 41 and attached parts in the desired position, it being in that shown in Figs. 1 to 3 when the jack is used for lifting and that of Figs. 4 to 10 when it is adapted for lowering. This plate has an enlargement 43 on its lower end, which acts as a stop for the lower end 44 of lifting-lever socket 25. Y

Attached to the inside of plate 41 by' means of a screw 45 is a iiexible spring 46, having its lower end 47 bent around the lower end of the plate 41, as shown. This spring lies in a rectangular slot 4S, cut in the back ofv standard 16 (and covered by the plate 41) and has a portion 49, extending' inside of the jack, adapted to engage with a lug 50 on the lower end of vpawl 26. Pivoted at 51 to arm 52,extending out from plate 41 through a slot in sprin\g46, is a finger Y53,"adapted to bear against the back ofw-pawl 26 when it is in the position shown in Fig. 5. This inger 53 has-a base 54, adapted in the same position to bear against spring 46.

Pivotally mounted at 27 on the same journal as pawl 26, either in the middle of the pawl, as shown, or at one side, is a finger 56, having its upper end adapted to engage the upper pawl 34 when the lifting-lever is depressed to the position shown in Fig. 6. This finger 56 has a lug or tailpiece .57, adapted to engage the part 49 of the spring 46.

Suppose there is a load on top of the 'lifting-bar which it is desired to lower notch by notch, or, in other words, pump down, and the jack to be in the position shown in Fig. 4, the load being locked by the upper pawl 34. The operator depresses lifting-lever 25, thereby moving pawl 26 and finger 56 up to theposition shown in Fig. 5; but in so doing the lug 50 of the lower pawl 26 has been moved along and against spring-cam 49, and thus held clear of teeth 37 of the lifting-bar. In the position shown in Fig. 5 this lug is just ready to escape from control of the spring and allow the pawl to fall into engagement with the teeth of the lifting-bar. This operation is assisted by the fact that the finger 53 now presses against the back of the pawl, and the base 54 of this finger presses against the spring, tending to cause it to release its hold upon the pawl. This construction is designed to insure the engagement of the lower pawl with the lifting-bar before the upper pawl can possibly be released, thus making sure that the load does not drop more than the desired amount of one tooth at a time. As the pawl 26 and iinger A56y are moved upward from the position shown in Fig. 5 to the position of Fig. 6, the lower pawl falls into engagement-with the teeth of the lifting-bar, and the tailpiece 57 of the finger 56 comes into engagement with the springcam 49, which throws the finger iirst to the position shown in full lines and finally to the dotted-line position of Fig. 6, thus throwing the upper pawl 34 out of engagement with the teeth of the lifting-bar. The shape of the tailpiece 57 and its relation to the spring 49 is such that the iinger 56 will hold this upper pawl out of engagement with the teeth of the lifting-bar, so as to pass one tooth as the bar descends. The operator now starts to raise the lifting-lever, thereby moving pawl 26, lifting-bar 18, and finger 56 downward. As indicated above, the upper pawl is held out of engagement untilr one tooth is passed, when it drops into engagement with the lifting-bar, thus stopping and locking the load. The operator continues the upward motion of the lifting-lever and the lower pawl clicks idly over part of one tooth of the lifting-bar. When the parts reach the position shown in Fig. 4, the spring 49 snaps into the notch above the lug 50 on the pawl. When the operator starts to reverse the motion of the lifting-lever, the disengagement of the pawl is completed and the entire operation is repeated.

I do not limit myself to the shape or material or exact arrangement of parts shown, as a wide range of equivalents may be substituted without departing from my invention.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, isp 1. In a lifting-jack, the combination of a standard, a lifting-bar, a lifting-lever, a pawl mounted on the stan dard, another pawl adapted to be reciprocated by the lifting-lever, a hook upon the lower pawl and a hook 'upon the upper pawl, said hooks .being so located and shaped that when the pawls both engage the lifting-bar the hooks or pawls will not engage each other at any point during the IOC) IIO

full stroke of the lifting-lever and also so located that when the loWer pawl is disengagedfrom the lifting-bar said hooks can engage each other and the upper paWl be thrown out of engagement with the lifting-bar at the extreme downward limit of the stroke of' the lifting-lever, substantially as described.

2. In a lifting-jack, the combination of a standard, a lifting-bar, a lifting-lever, a paWl 3. In a lifting-jack, the combination of a standard7 a lifting-bar, alifting-lever, apaWl mounted on the standard, another paWl and a pivotally-mounted finger adapted to be reciprocated by the lifting-lever; and yielding cam. mechanism adapted to make the latter pawl clear the teeth of the lifting-bar during one portion of the stroke of the lifting-lever and adapted to cause said linger to trip the nist-mentioned pawl during another portion of the stroke of the lifting-lever.

4, In a lifting-jack, the combination of a standard, alifting-bar, alifting-lever, a paWl mounted on the standard, another pawl and finger pivotally'mounted on the lifting-lever, and vyielding cam mechanism adapted to make the latter pawl clear the teeth of the lifting-bar during one portion of the stroke of the lifting-lever and adapted to cause said linger to trip the iirst-mentioned ypaWl during another portion of the stroke of the liftinglever.

5. In a lifting-jack, the combination of a standard, a lifting-bar, a lifting-lever, a paWl mounted on the standard7 another pawl and a pivoted finger adapted to be reciprocated by the lifting-lever, and a spring cam mechanism mounted on the standard adapted to act upon said pawl andiinger and cause said pawl to clear therteeth of the lifting-barv during one portion of the stroke of the liftinglever and adapted to cause said Viingerto trip the rst-mentioned paWl during another por-v tion of the stroke of said lifting-lever.

6. ln a lifting-jack, the combination of a standard, a lifting-bar, a lifting-lever, a pawl mounted on the standard, another paWl and a pivoted finger adapted to be reciprocated by the lifting-lever, a spring cam mechanism mounted on the standard adapted to act upon said paWl and nger and cause said paWl to clear the teeth of the lifting-bar during one portion of the stroke of the lifting-lever and adapted to cause said iinger to trip the iirstmentioned paWl during 'another portion of the stroke of the lifting-lever, and mechanism adapted to bear simultaneously against said spring and moving paWl toinsure the release of the pawl from the spring at the desired point, substantially as described.

' 7'i In a lifting-jack, the combination of a standard, a lifting-bar, a lifting-lever, a pawl mounted on the standard, another pawl and a pivoted finger adapted to be reciprocated by the lifting-lever, a spring cam mechanism mounted on the standard adapted to act upon r said pawl and finger and cause said paWl to clear the teeth of the lifting-bar during one portion of the stroke of the lifting-lever and adapted to cause said finger to trip the iirstcuring saidspring cam mechanism in posimentioned pawl during another portion of the strokeof the lifting-lever, means for se tion to perform-the foregoing functions and means for securing said mechanism in another i position on thestandard Where it Will be incapable of acting, substantially as described. 8. In a lifting-jack, the combination of a standard, a lifting-bar, a lifting-lever,V a pawl mounted on the standard, another pawl piV# V,oted on the lifting-lever, a lug on said pawl, a finger pivoted to said lifting-lever adapted `to temporarily engage the first pawl, alug on said linger, a spring-cam mounted on the standard adapted to engage the lugs on said pawl and finger and move them as described When the lifting-lever is raised and lowered.

EUGENE M. ROBINSON.

Witnesses vRonnn'r CATHERWOOD, DWIGHT B. GHEEVER.' 

